Photoinduced electron transfer between fullerenes (C60 and C70) and phthalocyanines such as tetra-tert-butylphthalocyanine (H2TBPc) and its zinc derivative (ZnTBPc) in solution has been investigated with nanosecond laser photolysis method by observing the transient absorption bands in the visible/near-IR regions. By the predominant excitation of fullerenes with 532 nm laser light, slow rises of the transient absorption bands of phthalocyanine cation radicals and fullerene anion radicals were observed instead of the decays of the excited triplet states of fullerenes (TC60* and TC70*) in polar solvents. Electron-transfer from the phthalocyanines to TC60* or TC70* was confirmed. The quantum yield of the electron transfer via TC70* is higher than that via TC60*; ZnTBPc acts as stronger electron donor than H2TBPc. In nonpolar solvent, energy transfer from TC60* (and TC70*) to the phthalocyanines occurs predominantly as confirmed by the consecutive appearance of the triplet states of the phthalocyanines.

The basal plane of graphene has been known to be less reactive than the edges, but some studies observed vacancies in the basal plane after reaction with oxygen gas. Observation of these vacancies has typically been limited to nanometer-scale resolution using microscopic techniques. This work demonstrates the introduction and observation of subnanometer vacancies in the basal plane of graphene by heat treatment in a flow of oxygen gas at low temperature such as 533 K or lower. High-resolution transmission electron microscopy was used to directly observe vacancy structures, which were compared with image simulations. These proposed structures contain C═O, pyran-like ether, and lactone-like groups.

BackgroundHuman T-cell leukemia virus type 1 (HTLV-1) causes chronic infection leading to development of adult T-cell leukemia (ATL) and inflammatory diseases. Non-human primates infected with simian T-cell leukemia virus type 1 (STLV-1) are considered to constitute a suitable animal model for HTLV-1 research. However, the function of the regulatory and accessory genes of STLV-1 has not been analyzed in detail. In this study, STLV-1 in naturally infected Japanese macaques was analyzed.ResultsWe identified spliced transcripts of STLV-1 corresponding to HTLV-1 tax and HTLV-1 bZIP factor (HBZ). STLV-1 Tax activated the NFAT, AP-1 and NF-κB signaling pathways, whereas STLV-1 bZIP factor (SBZ) suppressed them. Conversely, SBZ enhanced TGF-β signaling and induced Foxp3 expression. Furthermore, STLV-1 Tax activated the canonical Wnt pathway while SBZ suppressed it. STLV-1 Tax enhanced the viral promoter activity while SBZ suppressed its activation. Then we addressed the clonal proliferation of STLV-1+ cells by massively sequencing the provirus integration sites. Some clones proliferated distinctively in monkeys with higher STLV-1 proviral loads. Notably, one of the monkeys surveyed in this study developed T-cell lymphoma in the brain; STLV-1 provirus was integrated in the lymphoma cell genome. When anti-CCR4 antibody, mogamulizumab, was administered into STLV-1-infected monkeys, the proviral load decreased dramatically within 2 weeks. We observed that some abundant clones recovered after discontinuation of mogamulizumab administration.ConclusionsSTLV-1 Tax and SBZ have functions similar to those of their counterparts in HTLV-1. This study demonstrates that Japanese macaques naturally infected with STLV-1 resemble HTLV-1 carriers and are a suitable model for the investigation of persistent HTLV-1 infection and asymptomatic HTLV-1 carrier state. Using these animals, we verified that mogamulizumab, which is currently used as a drug for relapsed ATL, is also effective in reducing the proviral load in asymptomatic individuals.

Photoinduced electron transfer between C60/C70 and zinc tetraphenylporphyrin (ZnTPP) in a polar solvent has been investigated with a nanosecond laser photolysis method by observing the transient absorption bands in the near-IR region. The transient absorption bands of the C60/C70 radical anion (C60 •-/C70 •-) in the near-IR region gave evidence of electron transfer for the system ZnTPP and C60/C70. In ZnTPP solution where C60 and C70 were photoexcited predominantly, electron transfer takes place from the ground state of ZnTPP to the triplet states of C60/C70 (3C60*/3C70*). In the concentrated ZnTPP solution where ZnTPP was predominantly photoexcited, the triplet state of ZnTPP donates the electron to the ground state of C60/C70, producing C60 •-/C70 •-. The efficiency of electron transfer via the 3C60*/3C70* route is higher than that via 3ZnTPP*.

Emission measurements were performed on a series of σ-π conjugated organosilicon copolymers, -[(SiMe2)mA]n-(m ) 1, 2, 3, 4, and 6), with alternating dimethylsilylene and π-conjugated units (A ) phenylene, diphenylene, and anthranylene) in various solvents. The copolymers with m g 2 exhibit a broad emission ascribable to an intramolecular charge transfer (CT) excited state resulting from the charge transfer between the dimethylsilylene and aromatic units. The solvatochromism of the emission spectra was observed for the organosilicon copolymers, where the emission maximum shifted to longer wavelength in polar solvents. The influence of the dimethylsilylene chain-length and the π-conjugated unit on the CT emission was investigated. The molecular orbital calculations on a model compound suggest that the vibronically structured emission is attributed to the π-character of the aromatic unit, and the structureless broad emission is ascribed to the σ-character of the Si-Si bond in the excited states. The emission lifetime and the quantum yield also show the dimethylsilylene chain-length dependence.